This is WEEKEND EDITION from NPR News. I'm Rachel Martin. Looking back on the year, one of the biggest newsmakers of 2012 was Mother Nature. This year saw drought conditions in more than half of the lower 48 states, the worst since the 1950s. Wildfires consumed close to 10 million acres of land across the country. And Superstorm Sandy brought unprecedented destruction to New York and New Jersey. To talk more about this year's weather, I spoke with Michael Lemonick. He's a senior writer at Climate Central, an independent research and journalism organization. And he says there's another reason 2012 may be a benchmark year for weather.

MICHAEL LEMONICK: We've had the warmest year on record and we can declare that now even though the year is not quite over because it would have to be so cold in the last few weeks of December to prevent it from being the warmest on record that it's essentially impossible. We had - not in the U.S. - but up in the Arctic a record melt-back of the ice on the Arctic Ocean at the end of the summer. And that has all sorts of follow-on climate effect, including possibly - although it's not certain yet - the idea that warmer Arctic summers can lead to more severe winters in the U.S. and North America in general and also in Europe.

MARTIN: There are usually a lot of caveats when someone talks about climate change being responsible for extreme weather. But is that changing at all? Do you think is the direct link between these extreme weather events and climate change getting stronger?

LEMONICK: Yes, it's absolutely getting stronger. Every year, it gets stronger. It's still not 100 percent because there are natural climate variations that go on all the time, whether or not we have global warming. And so...

MARTIN: What do you mean by natural variations, if I can?

LEMONICK: Oh well, ocean currents are a big one. Also, you know, volcanoes go off. That cools things off for a while. The sun itself gets a little brighter or gets a little dimmer. All those are natural climate variations. But the global warming signal, which for the first maybe two-thirds of the 20th century was invisible underneath those natural variations started to emerge and it's getting stronger and stronger. So, every year that goes by the human-caused climate change signal is overwhelming the natural signal more and more.

MARTIN: Is there any evidence to demonstrate whether or not this year's extreme weather has moved public opinion when it comes to climate change?

LEMONICK: There have been a number of surveys done which show that people are connecting extreme weather to climate change more than they ever had before. They are looking around them and seeing these events. And because journalists and scientists are talking about climate change and explaining the connection, yes, people are putting those things together.

MARTIN: If we assume that this is not going to stop any time soon, that we're going to continue to see these extreme weather events, is there anything that local municipalities are doing in advance of that to prepare?

LEMONICK: Local municipalities are really waking up and seeing the direct effects of these extreme weather events. They are talking about and thinking about better evacuation plans for people who live along the shore as hurricanes threaten. They're talking about water supplies in the event of future droughts, which climate scientists predict are going to come more often. They're thinking about everything that could be tied in with extreme weather; putting electric wires underground. Most of the power lost during Hurricane Sandy was lost because tree limbs, entire trees fell on power lines.

MARTIN: How is it affecting us in a personal way? I mean, a lot of these weather events affect people in incomprehensible ways. I mean, lives are lost. Are these weather events, are they starting to change or to anticipate that they will begin to change our behavior, how we live our lives?

LEMONICK: It's a really good question, and I am reluctant to say that our attitude toward climate change, or especially our political leaders' attitude toward climate change is going to lead to changes in our behavior. I talk about political leaders because they are really the ones whose behavior matters the most. You know, we can change all the light bulbs we want and go buy a Prius or insulate our houses, do the kinds of feel-good things that we've talked about for years, but that alone is not going to reduce the growth of greenhouse gases in a significant enough way to hold back climate change. That's going to take political action, international political action. But I believe that at some point they will wake up and they will realize they have to do something about this, and it may well be that that's starting now. There's certainly talk of it.

MARTIN: So, you're saying when you look back at 2012, you see this as a tipping point of sorts when it comes to policies surrounding climate change?

LEMONICK: I can't say that I see it as a tipping point. I can say that when we look back from the perspective of 10 years down the road, it made in retrospect be a tipping point. We may find out a year from now that everybody's forgotten about it or we may find out that this time the signals we're getting from the climate are sticking and that people are finally taking action.

MARTIN: Michael Lemonick with Climate Central, an independent group of journalists and scientists. He's the co-author of "Global Weirdness." His most recent book is called "Mirror Earth," about the search for a planet that could support life. Michael, thanks so much for talking with us.